This invention is related to a token ring wiring concentrator and specifically to a lobe used in a token ring wiring concentrator for switching a workstation in and out of the system. Such a system is usually referred to as a "Multi-station Access Unit" or MAU. Such system is provided for in IEEE/ANSI 802.5 specification which refers to such system as a "Trunk Coupling Unit." Single lobes are combined with other identical lobes to form a complete concentrator. While the number of lobes in a concentrator can vary, the most popular configuration utilizes eight lobes and such is due primarily to the physical size of the token ring connector as it fits in a standard equipment rack.
As previously stated, the function of a Multi-station Access Unit is to electrically insert and remove a workstation from the system or more specifically, to connect or remove a workstation from a token ring network. Control of the inserting or removing a workstation from a token ring network is accomplished, as provided in the IEEE/ANSI standards, by means of DC voltage that is sometimes referred to as a "phantom voltage." This phantom voltage is applied between two pairs of conductors in the data cable that connects the workstation to the Multi-station Access Unit. When the phantom voltage is present at a preselected potential, the Multi-station Access Unit functions to insert the workstation into the network. When the phantom voltage is absent or falls below a preselected level, the workstation is removed from the network.
For background reference to information relating to the subject of this disclosure, reference may be made to IEEE/ANSI standards 802.5. For reference to previously issued United States Patents concerning the general subject matter of this disclosure, reference may be had to the following: U.S. Pat. Nos. 4,674,086; 4,905,230; 4,701,630; 4,696,047; 4,810,898; 4,782,245; 4,484,086; 4,825,095; 4,823,023; 4,820,935; 4,835,406; 4,674,086; 4,527,216; 4,701,630 and RE32,516.